The Spotted Lanternfly (Lycorma delicatula) is an invasive planthopper from Asia that poses a significant threat to agriculture and ecosystems across North America. First detected in the United States in Pennsylvania in 2014, this pest has spread rapidly, infesting numerous states in the eastern regions. The lanternfly feeds on the sugary sap (phloem) of over 70 plant species, including economically important crops like grapes, apples, and stone fruits, as well as hardwood trees such as maple and black walnut. This feeding weakens the host plants, reducing crop yields and making trees vulnerable to other diseases and stressors.
The insects excrete large amounts of a sugary waste product called honeydew, which promotes the growth of black sooty mold. This mold covers plants and surfaces, inhibiting photosynthesis and creating an outdoor nuisance. Controlling this pest requires a multi-pronged approach that targets all life stages to slow its spread and mitigate damage.
Immediate Manual Eradication
The simplest and most immediate method of control involves physical removal and destruction of the insects. Both the wingless nymphs and the flying adults can be killed by crushing or stomping them upon sight. This method is highly effective for individual insects or small clusters and does not introduce any chemicals into the environment.
For larger, localized infestations, a wet vacuum can be employed. Using a shop vacuum filled with a small amount of soapy water or rubbing alcohol will instantly capture and kill the insects. This approach allows for the quick removal of high-density populations without relying on sprays. The vacuum contents must be properly sealed and disposed of afterward.
Passive Trapping Techniques
Setting up passive traps is an effective way to continuously reduce the population, especially the climbing nymphs. The most effective non-chemical trap is the circle trap, a funnel-style device wrapped around the tree trunk. As nymphs attempt to climb back up the trunk, they are guided into a dead-end collection container.
Traditional sticky bands can capture large numbers of nymphs, but they pose a risk to non-target species like birds, bats, and beneficial insects. If sticky bands are used, they must be protected by a barrier of vinyl mesh screening or chicken wire to prevent wildlife from contacting the adhesive. Traps should be placed approximately four feet from the ground, secured tightly to the tree, and monitored frequently.
Targeted Chemical Applications
Chemical control offers a more potent option, but requires careful application to minimize environmental impact. Low-toxicity topical sprays, such as insecticidal soaps, neem oil, and horticultural oils, are effective against nymphs when applied directly to the insects. These contact sprays generally have little residual activity, meaning they only kill the lanternflies they physically cover.
For heavier infestations or for targeting adults on high-value trees, stronger contact or systemic insecticides may be necessary. Contact insecticides like pyrethrins or bifenthrin provide a quick kill and can be used as spot treatments. Systemic insecticides, such as dinotefuran or imidacloprid, are absorbed by the plant and kill the lanternflies as they feed. Systemic treatments should be applied after the tree has finished flowering, typically from mid-July through September, to protect pollinators. Always strictly follow the product label instructions to ensure safety and compliance with local regulations.
Disrupting the Life Cycle
Targeting the stationary egg masses provides a highly effective preventative measure to reduce the next generation’s population. Spotted Lanternflies lay their eggs from late summer into early winter, and these masses survive the winter to hatch in the spring, typically in April or May. Each mass contains between 30 and 50 eggs, making their destruction a significant control effort.
The egg masses appear as a smear, roughly 1.5 inches long, often covered in a protective layer that looks like dried mud or putty. They can be found on nearly any hard surface, including trees, rocks, outdoor furniture, and vehicles. To destroy them, scrape the mass off the surface using a stiff tool like a putty knife, credit card, or plastic scraper. The scraped masses must then be immediately sealed in a container or plastic bag filled with rubbing alcohol or hand sanitizer to ensure the eggs are completely killed.